//使用Maybe重写ex4，不要有任何if语句
const fp = require('lodash/fp')
const {Maybe,Container} = require('./03-code')
// let ex4 = function (n){
  // if(n){
  //   return parseInt(n)
  // } 
// }
let ex4 = Maybe.of(4)
            .map(x => parseInt(x))
console.log(ex4)